Composite Petroleum System and Advantageous Exploration Targets in the Kongquehe Area of Tarim Basin

Guided by the description methods and evaluation routine for composite petroleum system in superimposed basins, the composite characteristics of the petroleum systems in the Kongquehe area of the Tarim basin was studied and the geological evolution processes of hydrocarbon from source to trap was revealed. The petroleum systems in the Kongquehe area, mainly through fault composite linkage combined with unconformity surface composite linkage, constitute the Cambrian € (!)–Lower Ordovician O1 (!)–Carboniferous C (*)–Triassic T (*)–Jurassic J (*) + Cambrian € (!)–Lower Ordovician O1 (*)–Silurian S (*)–Devonian D (*)–Jurassic J (*) modified composite petroleum systems (*). There are three critical periods for composite petroleum system, such as the end of Devonian for forming tectonic framework and paleoreservoir, the end of Jurassic and Cretaceous for hydrocarbon transformation, redistribution, and adjustment. The research area may be classified into three types— destroyed dissipation zone, transformed adjustment zone, and deeply-buried preservation zone, amongst which the latter two zones are favorable for hydrocarbon accumulation. Especially, the Upper Paleozoic and Mesozoic faulted anticline traps of the Longkou anticline and the Weimake–Kaiping anticline and the residual Lower Paleozoic fault paleo-anticline traps in the transformed adjustment zone are the best prospecting targets.